Flame retardancy,antifungal efficacies,and physical–mechanical properties for wood/polymer composites containing zinc borate

This work aimed to examine flame retardancy, antifungal performance and physical–mechanical properties for silane‐treated wood–polymer composites (WPCs) containing zinc borate (ZnB). ZnB with content from 0.0 to 7.0 wt% was added to WPCs, and silane‐treated wood contents were varied. The polymers used were poly(vinyl chloride) (PVC) and high‐density polyethylene (HDPE). The decay test was performed according to the European standard EN 113. Loweporus sp., a white‐rot fungus, was used for antifungal performance evaluation. Antifungal performance was observed to decrease with wood content. Incorporation of ZnB at 1.0 wt% significantly increased the antifungal performance of WPCs. ZnB content of greater than 1.0 wt% lowered the antifungal properties of WPCs. The results suggested that the wood/PVC composite exhibited better antifungal performance than the wood/HDPE composite. The addition of wood flour to PVC and HDPE decreased flame retardancy, whereas the incorporation of ZnB retained the flame retardancy. ZnB was found to be more appropriate for wood/PVC than wood/HDPE as a result of hydrogen chloride generated from the dehydrochlorination reaction of PVC. The results indicated that the addition of ZnB did not affect the physical‐mechanical properties of neat polymers and the composites. Copyright © 2016 John Wiley & Sons, Ltd.     

Material Formulations for AR/PMMA and AR-TiO2/PMMA Blends and Effects of UV Radiation and Tio2 Loading on Mechanical and Antibacterial Performances

Polymer blends of poly(methyl methacrylate)(PMMA) and acrylic rubber(AR) were manufactured with the addition of titanium dioxide (TiO₂). TiO₂ was initially added to the AR phase in AR/PMMA blends. The impact strength of PMMA improved with AR loading. The addition of TiO₂ appeared to decrease the tensile properties of the blends with AR of 10-30?wt% of AR, but increased with AR of 40-50?wt%, this being related to distribution level of TiO₂. UV radiation deteriorated the overall mechanical properties, where TiO₂ could retain the properties. To achieve acceptable antibacterial performance, AR loadings of 40 and 50?wt% in AR-TiO₂/PMMA blends are recommended, together with TiO₂ loadings of 1.5?pph and 0.5?pph, respectively.     

Assessment and characterization of antifungal and antialgal performances for biocide‐enhanced linear low‐density polyethylene

In this work, four biocides were used for the purpose of growth inhibition of fungi and algae in linear low‐density polyethylene (LLDPE) specimens. Benzimidazol‐2‐yl‐carbamicacid methyl ester [carbendazim (CB)], 5‐chloro‐2‐(2,4‐dichlorophenoxy)phenol [triclosan (TS)], and 3‐iodo‐2‐propynyl N‐butylcarbamate [iodopropynyl butylcarbamate (IPBC)] were used as antifungal agents, and 2‐methylthio‐4‐ethylamino‐6‐tert‐butylamino‐triazin‐1,3,5 [terbutryn (TT)] was used as an antialgal agent. Antifungal performance was evaluated by disk diffusion and dry weight techniques, and antialgal activities were carried out by disk diffusion and chlorophyll A methods. Aspergillus niger TISTR 3245 and Chlorella vulgaris TISTR 8580 were used as the testing fungus and alga, respectively. The experimental results suggested that the wettabilities of LLDPE specimens changed with the incorporation of CB, TS, IPBC, and TT biocides without significant changes in chemical structures and mechanical properties of the LLDPE. IPBC with the recommended content of 10,000 ppm was found to give the most satisfactory growth inhibition of A. niger. Antifungal performance evaluations were dependent on the testing methods used, whereas those for antialgal activity were not. The optimum concentration of TT agent for effective killing of C. vulgaris was 750 ppm; this loading could be reduced from 750 to 250 ppm by the addition of either TS or IPBC agent. TS and IPBC could be used as antialgal promoters in the LLDPE specimens. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2013     

Effect of poly(D-lactic acid) and cooling temperature on heat resistance and antibacterial performance of stereocomplex poly(L-lactic acid)

Stereocomplex nucleated polylactic acid was prepared by the addition of poly(D-lactic acid) (PDLA) in poly(L-lactic acid) (PLLA) under various cooling temperatures by monitoring the mechanical properties and heat resistance. Antibacterial performance against the growth of Escherichia coli on PLLA/PDLA doped with various contents of 2-hydroxypropyl-3-piperazinyl-quinoline carboxylic acid methacrylate (HPQM) was also evaluated. The results suggested that a small addition of PDLA generated stereocomplex crystals while increasing cooling temperature resulted in homo crystals formation in PLLA. The incorporation of PDLA with high cooling temperature increased the heat deflection temperature, impact resistance, and tensile modulus, but decreased the antibacterial performance against E. coli. The addition of PDLA at 2.0 wt% in PLLA at cooling temperature at 80°C showed a synergistic effect to obtain an exceptionally high heat deflection temperature up to 164°C. HPQM was, for the first time, introduced as antibacterial agent in PLLA with an optimum dosage of 1750 ppm. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48970.